Buh JC, Sacha Cohen Baron - the guy famous for Borat ... D Ali G Show etc. is not Kazakh or any of the other roles he runs ... Haitian V is essentially doing the same thing, albeit on a more modest scale.
I don't think it's that relevant whether he's Haitian, but I believe he is.
I don't believe he speaks like that regularly. My take is that he grew up in the US and is satirising situations relying on that 'voice' of perhaps a stereotype. Sounds authentic to me based on 'voices' I've heard ... maybe one of the Haitian members will give their take.